MLK-15949-4 mmc: sdhci-esdhc-imx: restore the per_clk rate in PM_RUNTIME

When pm_runtime_suspend is run, a call to SCFW power off the SS in
which the resource resides is made. The SCFW can power off the SS
if no other resource in active in tha SS. If so, all state associated
with all the resources within the SS that is powered off is lost,
this includes the clock rates, clock state etc. When pm_runtime_resume
is called, the SS associated with that resource is powered up. But
the clocks are left in the default state.

This patch restore clock rate in pm_runtime_resume, make sure the
clock is right rather than depending on the default state setting
by SCFW.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index f9853c0..0abdc2b 100644 (file)
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -159,6 +159,8 @@
 #define ESDHC_FLAG_PMQOS               BIT(13)
 /* The IP supports HS400ES mode */
 #define ESDHC_FLAG_HS400_ES            BIT(14)
+/* The IP lost clock rate in PM_RUNTIME */
+#define ESDHC_FLAG_CLK_RATE_LOST_IN_PM_RUNTIME BIT(15)
 
 /* A higher clock ferquency than this rate requires strobell dll control */
 #define ESDHC_STROBE_DLL_CLK_FREQ      100000000
@@ -239,7 +241,8 @@ static struct esdhc_soc_data usdhc_imx8qm_data = {
        .flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
                        | ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
                        | ESDHC_FLAG_HS400 | ESDHC_FLAG_HS400_ES
-                       | ESDHC_FLAG_STATE_LOST_IN_LPMODE,
+                       | ESDHC_FLAG_STATE_LOST_IN_LPMODE
+                       | ESDHC_FLAG_CLK_RATE_LOST_IN_PM_RUNTIME,
 };
 
 struct pltfm_imx_data {
@@ -1551,6 +1554,9 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
                pm_qos_add_request(&imx_data->pm_qos_req,
                        PM_QOS_CPU_DMA_LATENCY, 0);
 
+       if (imx_data->socdata->flags & ESDHC_FLAG_CLK_RATE_LOST_IN_PM_RUNTIME)
+               clk_set_rate(imx_data->clk_per, pltfm_host->clock);
+
        if (!sdhci_sdio_irq_enabled(host)) {
                clk_prepare_enable(imx_data->clk_per);
                clk_prepare_enable(imx_data->clk_ipg);